In one type of automated testing equipment for microprocessor based digital circuitry in a unit under test, the microprocessor is removed from its socket and replaced by a plug to which is connected a tester that applies signals to the bus of the unit. The tester, which includes a microprocessor that emulates the microprocessor of the unit under test, applies signals on the bus at addresses corresponding to various components on the bus whose functions are to be tested. The automated testing equipment is programmed to compare signals read from the bus at addresses throughout the unit under test with predetermined signals to isolate circuit faults. An example of such automated testing equipment is given in Scott et al. U.S. patent application Ser. No. 761,027, filed on July 29, 1985, assigned to the assignee of this invention and incorporated herein by reference.
Operation of automated testing equipment of this type requires that the microprocessor be socketed so that it can be removed for replacement by the plug of the tester that will apply signals to and read response signals from the bus of the unit under test. However, to reduce the cost, and improve reliability of, microprocessor-based circuits there is a trend toward soldered-in, rather than socketed, semiconductor integrated circuits. A need therefore exists to apply automated testing equipment of the type described to soldered-in microprocessors and other semiconductor devices within units under test.
Accordingly, one object of the invention is to apply automated testing equipment to soldered-in semiconductor devices of a unit under test.
Another object of the invention is to provide an adapter clip to connect to the leads of a soldered-in integrated circuit within a bus-oriented, microprocessor-based unit under test for interfacing the unit with automated testing equipment emulating the unit microprocessor.
Another object of the invention is to provide access to all signal pins of a soldered-in integrated circuit through extended test points and to identify the
functions of the pins by name.
Still another object is to provide an adapter clip of a type described that has good mechanical and electrical integrity, and is easily applied to and removed from an integrated circuit within a unit under test.
A further object of the invention is to provide an adapter clip of the type described that is economically manufactured using conventional and commercially available components.